Cu-doped BCN nanofibers for highly selective adsorption desulfurization through S-Cu coordination and π-π interaction

Abstract

Boron carbon nitride (BCN) has emerged as an effective material owing to its high specific surface area, porous structure, and excellent chemical inertness. However, the existing BCN adsorbents for adsorption desulfurization (ADS) exhibit inferior adsorption capacity and selectivity. Herein, a series of novel BCN nanofibers doped with Cu(I) adsorption sites (BCN-Cu-X, X = 0.02, 0.04, 0.06, 0.08 mmol) were fabricated via a simple one-pot pyrolysis method derived from a carboxylic acid copper coordination compound. The results demonstrated that BCN-Cu-0.04 shows a remarkably increased adsorption capacity for dibenzothiophene (DBT) about 33% higher than BCN under the same conditions. It is also noteworthy to mention that BCN-Cu-0.04 presents high ADS performance even for the refractory sulfur compound 4,6-Dimethyldibenzothiophene (4,6-DMDBT, 42.2 mg S/g adsorbent). Furthermore, density functional theory (DFT) calculations proved that the enhanced performance of BCN-Cu-X in ADS is attributed to the π-π interaction and newly formed sulfur-copper (S-Cu) coordination bond, which is different from other Cu-based adsorbents. This study may inspire the development of new synthetic routes which are possible to realize high-efficiency and high-selectivity ADS.